Thermal conductivity against densityHigher and further left: spreads more heat for its weightThermal expansion against thermal conductivityLower and further right: warps less when heated
Try it on a partA sample part to run stress or thermal on, free in your browser
Northern red oak (Quercus rubra), clear straight-grained specimens at 12% MC, parallel to grain unless stated; USDA FPL Wood Handbook FPL-GTR-282 (2021) Ch. 4 and Ch. 5
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Wood Handbook (FPL-GTR-282), Chapter 12: Mechanical Properties of Wood-Based Composite MaterialsUSDA Forest Products LaboratoryPlywood · Ultimate tensile strength: modulus of rupture (no direct tensile value)Plywood · Flexural strength: static bending MOR (Douglas-fir); range 33.72-42.61 across speciesPlywood · Young's modulus (stiffness): static bending MOE of the panel (Douglas-fir); range 6.96-8.55 across species
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Wood Handbook (FPL-GTR-282), Chapter 5: Mechanical Properties of WoodUSDA Forest Products LaboratoryWood · Ultimate tensile strength: modulus of rupture (no direct tensile value)Wood · Compressive strength: compression parallel to grain (maximum crushing strength), 12% MCWood · Flexural strength: modulus of rupture (static bending), 12% MCWood · Young's modulus (stiffness): bending MOE, parallel to grainWood · Poisson's ratio: mu_LR (red oak group, ~12% MC)
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Technical Note 218: Weights of Various Woods Grown in the United States (1953)USDA Forest Products LaboratoryWood · Density: average weight of clear wood at 8% and 15% moisture content
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Thermal Properties of Wood and Wood Panel Products for Use in Buildings (1988)USDA Forest Products Laboratoryarchived copyPlywood · Thermal conductivity: APA-recommended design value (Douglas-fir plywood), as reported by FPL/ORNL
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Wood Handbook (FPL-GTR-282), Chapter 4: Moisture Relations and Physical Properties of WoodUSDA Forest Products LaboratoryWood · Thermal conductivity: across grain, 12% MC (Table 4-7, approximate)Plywood · Thermal expansion: base material: solid wood parallel to grain, ovendry, range across speciesWood · Thermal expansion: parallel to grain, ovendry wood, range across speciesPlywood · Specific heat: base material: solid wood (all species), 12% MC, 27 CWood · Specific heat: solid wood (all species), 12% MC, 27 C
Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Mechanical
Is Plywood stronger than Wood?
Wood is stronger: its tensile strength is 99 MPa against 41.4 MPa for Plywood (2.39x).
Which is stiffer, Plywood or Wood?
Wood is stiffer: Young's modulus 12.5 GPa against 7.45 GPa for Plywood, so the same part in Wood deflects less under the same load.
Thermal
Which conducts heat better, Plywood or Wood?
Wood conducts heat better: 0.18 W/m·K against 0.12 W/m·K for Plywood.
Which expands less with temperature?
Plywood expands less: 3.8 µm/m·K against 3.8 µm/m·K for Wood.